Essential Data Elements for Laboratory Test Interoperability: An Expert Consensus-Based Framework.

Onchocerciasis, also known as river blindness, is a debilitating parasitic infection caused by the filarial nematode Onchocerca volvulus. It is the second leading infectious cause of blindness worldwide, surpassed only by trachoma []. The disease manifests through various clinical signs and symptoms that significantly affect survival and socioeconomic conditions, particularly impacting women and children. Associations with conditions such as dwarfism (Nakalanga syndrome), cognitive impairments, epilepsy, nodding syndrome, increased mortality, diminished productivity, and social stigma have been documented [–]. As of 2017, approximately 21 million people were infected globally, with over 99% residing in 31 African nations, including Cameroon []. The World Health Organization (WHO) has endorsed community-directed treatment with ivermectin (CDTI) as the primary control strategy against onchocerciasis in Africa []. This approach has successfully interrupted or eliminated transmission in several regions of Latin America and specific African foci, including Uganda, Sudan, Senegal, Mali, and Nigeria, demonstrating its efficacy. Nonetheless, despite over two decades of CDTI implementation in Cameroon, onchocerciasis persists in 60% (113 out of 189) of the health districts across the country’s ten regions, with some districts reporting a prevalence exceeding 60% []. Challenges to eradication include high transmission rates due to significant vector presence, suboptimal treatment coverage attributed to absenteeism during campaigns, fear of adverse effects, and potential suboptimal ivermectin efficacy or emerging drug resistance []. Most studies reported that programmatic treatment coverage often falls below 80%, with around 10% of individuals consistently opting out of ivermectin administration (called systematic non compliers). Factors such as absence during mass drug administration campaigns, primarily among individuals under 40 who are likely to be at work, notably affect compliance rates. Additional barriers include logistical challenges in drug delivery by community drug distributors (CDDs) and resource constraints at the operational level of the National onchocerciasis control program (NOCP) [–]. These observations highlight limitations in IVM campaign planning and delivery that are hindering its potential as an effective onchocerciasis intervention. Given that absence during the campaign represents a significant barrier to this intervention, extending the duration for which medication remains available in the community may serve as a potential strategy to address this challenge.